From whatever starting year you pick, your main goal as Holland is to eventually form the Netherlands. In the 1444 start, you are going to want to break away from Burgundy when the time is right. If the Burgundians begin to get beat down in a war with France for example, that would be your time to declare a war for independence. As for idea groups, Exploration and Trade ideas are going to be by far the best choices for Holland due to your geographical location being in the English Channel trade node, as well as being closer to the New World than other European colonizers to the east.